Encyclopaedia of Travel Agency Management, Volume 1
Encyclopaedia of Travel Agency Management, Volume 2
Encyclopaedia of Travel Agency Management, Volume 3
Encyclopaedia of Agriculture, Volume 1: Elements of Agriculture
Encyclopaedia of Agriculture, Volume 2: Agriculture: The Cultivation
Encyclopaedia of Agriculture, Volume 3: Agriculture: Crop Pattern
Encyclopaedia of Agriculture, Volume 7: Agriculture: Soil and Water
Encyclopaedia of Agriculture, Volume 4: Agriculture: Crop Production
Encyclopaedia of Agriculture, Volume 5: Agriculture: Farming Methods
Encyclopaedia of Agriculture, Volume 6: Agriculture: Plant Protection